The neural cell adhesion molecule (N-CAM) engages in diverse functional roles in neural cell interactions. Its extracellular part consists of five Ig-like domains and two fibronectin type III homologous (type III) repeats. To investigate the functional properties of the different structural domains of the molecule in cell interactions and signal transduction to the cell interior, we have synthesized, in a bacterial expression system, the individual domains and tandem sets of individual domains as protein fragments. These protein fragments were tested for their capacity to influence adhesion and spreading of neuronal cell bodies, promote neurite outgrowth, and influence cellular migration patterns from cerebellar microexplants in vitro. Ig-like domains I and II and the combined type III repeats I-II were most efficient for adhesion of neuronal cell bodies, when coated as substrates. Neurite outgrowth was best on the substrate-coated combined type III repeats I-II, followed by the combined Ig-like domains I-V and Ig-like domain I. Spreading of neuronal cell bodies was best on substrate-coated combined type III repeats I-II, followed by Ig-like domain I and the combined Ig-like domains I-V. The cellular migration pattern from cerebellar microexplant cultures plated on a mixture of laminin and poly-L-lysine was modified by Ig-like domains I, III, and IV, while Ig-like domains II and V and the combined type III repeats I-II did not show significant modifications, when added as soluble fragments. Outgrowth of astrocytic processes from the explant core was influenced only by Ig-like domain I. Metabolism of inositol phosphates was strongly increased by Ig-like domain I and less by the Ig-like domains II, III, IV, and V, and not influenced by the combined type III repeats I-II. Intracellular concentrations of Ca2+ and pH values were increased only by the Ig-like domains I and II. Intracellular levels of cAMP and GMP were not influenced by any protein fragment. These experiments indicate that different domains of N-CAM subserve different functional roles in cell recognition and signal transduction, and are functionally competent without nervous system-derived carbohydrate structures.

Records of different pollen were used to examine associations with weather parameters for the three different pollen: hazel (Corylus sp.), birch (Betula sp.) and grass (Poaceae). As air temperature is expected to rise according to the forecasts from the Intergovernmental Panel on Climatic Change (IPCC) and as this factor has a great potential to affect the development of plants, the records of different pollen were used to understand possible associations. The analysis of weather data for the studied period showed a significant increase in the annual mean temperature. From an aerobiology point of view it is most important to note that the temperature increase in winter (December) becomes most evident. As a consequence of this, hazel started earlier to flower. The flowering period which was originally in March thus shifted to January and February. Therefore the time period for hay fever patients shifted also partly to the traditional winter period. The starting season for birch and grass was not that much influenced by the temperature shift. However, regarding these two plants I also found that the wanner the weather preceding the flower period, the earlier the plants start to emit pollen. The total pollen count increased for the observed time period for all three investigated taxa. The reason for this increase is not obvious, but it is conceivable that the observed temperature rise may exert an influence. The observed pollen count increase goes hand in hand with the observed increase in pollen allergies. However, a direct link could not be ascertained yet. The increase of temperature and the corresponding shift of the flowering time of plants whose pollen are of special interest in this connection has a medical significance since the period for hay fever sufferers becomes longer and can nowadays last from January (starting with hazel) until September (ending with mugwort) in Switzerland. In addition, the analysis of weather data showed that the amount of precipitation did not change significantly over the observed time period, although precipitation increased slightly. A strong negative correlation between pollen number and the amount of precipitation was especially found for birch and grass.

The objective of this study was to evaluate the effect of heat waves on flares of inflammatory bowel disease (IBD) and infectious gastroenteritis (IG). In this retrospective controlled observational study, data from 738 IBD and 786 IG patients admitted to the University Hospital of Zurich in the years 2001–2005, as well as from 506 other noninfectious chronic intestinal inflammations, which were used as control, were collected. Climate data were obtained from the Swiss Federal Office for Meteorology and Climatology. The presence of a heat wave increased the risk of IBD flares by 4.6% (95% confidence interval (CI): 1.6–7.4%, P=0.0035) and of IG flares by 4.7% (95% CI: 1.8–7.4%, P=0.0020) for every additional day within a heat wave period. In the control group there was no significant effect (95% CI: −6.2–2.9%, P=0.53). Screening of alternative forms for the effect of heat waves suggested that for IG the effect is strongest when lagged by 7 days (risk increase per day: 7.2%, 95% CI: 4.6–9.7%, P<0.0001), whereas for IBD no such transformation was required. Other formulations with additive effects, interactions between heat waves and time of the year, and additional adjustments for daily average temperature did not show any improvement in model fit. In this retrospective controlled observational study, we found a substantial increase in hospital admissions because of flares of IBD and IG during heat wave periods. Whereas the effect on IG is strongest with a delay of 7 days, the effect on IBD flares is immediate, suggesting different mechanisms.

The World Health Organisation (WHO) and the World Meteorological Organisation (WMO) have jointly recommended that the UV Index (UVI) should be used to inform the public about possible health risks due to overexposure to solar radiation, especially skin damage. To test the current operational status of measuring and modelling techniques used in providing the public with UVI information, this article compares cloudless sky UVIs (measured using five instruments at four locations with different latitudes and climate) with the results of 13 models used in UVI forecasting schemes. For the models, only location, total ozone and solar zenith angle were provided as input parameters. In many cases the agreement is acceptable, i.e. less than 0.5 UVI. Larger differences may originate from instrumental errors and shortcomings in the models and their input parameters. A possible explanation for the differences between models is the treatment of the unknown input parameters, especially aerosols. Copyright © 2001 Royal Meteorological Society